Skip to main content
Advanced Search

Filters: Tags: Modeling (X)

715 results (49ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
The paper traces the manner in which an obligation came to be imposed on select industries, requiring them to take account of amenity, wildlife and outdoor-recreational interests in the course of preparing and carrying out developmental schemes. Under pressure from the relevant voluntary bodies, the statutory obligations, first imposed on hydro-electric power development, were generalized to cover 'whole' industries, and then, under the Countryside Acts of 1967-68, were extended to all State utilities. The recent privatization of those industries has provided a further pretext for extending and strengthening the 'amenity' clause. The approach has provided important insights into how industry itself might become...
This paper proposes a regional and sectoral model of global final energy demand. For the main end-use sectors of consumption (industrial, commercial and public services, residential and road transportation), per-capita demand is expressed as an S-shaped function of per-capita income. Other variables intervene as well, like energy prices, temperatures and technological trends. This model is applied on a panel of 101 countries and 3 aggregates (covering the whole world) and it explains fairly well past variations in sectoral, final consumption since the beginning of the 2000s. Further, the model is used to analyze the dynamics of final energy demand, by sector and in total. The main conclusion concerns the pattern...
To determine the dominant processes controlling nitrogen (N) dynamics in soils and increase insights into soil N cycling from nitrogen isotope (?15N) data, patterns of 15N enrichment in soil profiles were compiled from studies on tropical, temperate, and boreal systems. The maximum 15N enrichment between litter and deeper soil layers varied strongly with mycorrhizal fungal association, averaging 9.6 � 0.4? in ectomycorrhizal systems and 4.6 � 0.5? in arbuscular mycorrhizal systems. The 15N enrichment varied little with mean annual temperature, precipitation, or nitrification rates. One main factor controlling 15N in soil profiles, fractionation against 15N during N transfer by mycorrhizal fungi to host plants, leads...
thumbnail
A comprehensive list of 38 categories of anthropogenic drivers of change in marine ecosystems developed through expert workshops (S1) was assessed for data availability on a global scale. We intentionally did not further subdivide these categories into unique drivers (e.g. each specific type of pollutant) as this would lead to over-emphasis of certain activities when impacts are summed. We limited our analyses to anthropogenic drivers with pre-existing global coverage or those for which we could assemble or develop global coverage. Although many regional-scale data and data with a global scope but incomplete coverage exist for a variety of specific human activities, inclusion of these data would bias global comparisons...
thumbnail
This dataset represents presence of white pine (Pinus strobus) at year 100 (2095) from a single model run of LANDIS-II. The simulation assumed Intergovernmental Panel on Climate Change (IPCC) B2 emissions (moderate) and used the Hadley 3 global circulation model. Contemporary harvest rates and intensities were simulated.
thumbnail
Climate and land-use change are major components of global environmental change with feedbacks between these components. The consequences of these interactions show that land use may exacerbate or alleviate climate change effects. Based on these findings it is important to use land-use scenarios that are consistent with the specific assumptions underlying climate-change scenarios. The Integrated Climate and Land-Use Scenarios (ICLUS) project developed land-use outputs that are based on a downscaled version of the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines. ICLUS outputs are derived from a pair of models. A demographic...
thumbnail
We will develop a set of linked models to help predict the effects of climate change on rivers and endangered species. These will include watershed- and reach-scale models to predict streamflow, water temperatures, and other fish habitat metrics under various climatic scenarios for the reaches used by species listed under the Endangered Species Act (ESA), plus a combined bioenergetics and life-cycle model (to be done by the U.S. Geological Survey [USGS]) to assess the impact of these factors on fish growth, reproduction, and survival. We propose to test the model framework at a site on the Methow River, Washington, to explore additional opportunities for collaboration and model development.
thumbnail
This dataset represents presence of Jack Pine (Pinus banksiana) in Minnesota (USA) at year 50 (2045) from a single model run of LANDIS-II. The simulation assumed Intergovernmental Panel on Climate Change (IPCC) B2 emissions (moderate) and used the Hadley 3 global circulation model. Restoration harvest rates and intensities were simulated.
thumbnail
This dataset represents presence of Sugar Maple (Acer saccharum) in Minnesota (USA) at year 0 (2145) from a single model run of LANDIS-II. The simulation assumed Intergovernmental Panel on Climate Change (IPCC) B2 emissions (moderate) and used the Hadley 3 global circulation model. Contemporary harvest rates and intensities were simulated.
thumbnail
This thesis is an investigation of the biophysical controls on the three modes of methane (CH4 ) release from a boreal peatland: diffusion, plant-mediated transport and ebullition. My objectives were to (1) quantify the total CH4 flux of a permafrost thaw-affected peatland, (2) establish the relative importance of the three modes of CH4 release in these systems, and (3) identify key biotic and abiotic controls on individual transport mechanisms. Results showed that ebullition and plant-mediated transport were the dominant pathways for CH4 release and that traditional approaches for measuring total CH4 flux from peatland soils underestimated total efflux by not capturing ebullition. Further, results from a laboratory...
thumbnail
The evolution of permafrost in cold regions is inextricably connected to hydrogeologic processes, climate, and ecosystems. Permafrost thawing has been linked to changes in wetland and lake areas, alteration of the groundwater contribution to streamflow, carbon release, and increased fire frequency. But detailed knowledge about the dynamic state of permafrost in relation to surface and groundwater systems remains an enigma. Here, we present the results of a pioneering 1,800 line-kilometer airborne electromagnetic survey that shows sediments deposited over the past 4 million years and the configuration of permafrost to depths of 100 meters in the Yukon Flats area near Fort Yukon, Alaska. The Yukon Flats is near the...
thumbnail
Issue Title: Special Issue: Science Results from the Canadian International Polar Year 2007-2008 Tundra and taiga ecosystems comprise nearly 40 % of the terrestrial landscapes of Canada. These permafrost ecosystems have supported humans for more than 4500 years, and are currently home to ca. 115,000 people, the majority of whom are First Nations, Inuit and Métis. The responses of these ecosystems to the regional warming over the past 30-50 years were the focus of four Canadian IPY projects. Northern residents and researchers reported changes in climate and weather patterns and noted shifts in vegetation and other environmental variables. In forest-tundra areas tree growth and reproductive effort correlated with...
thumbnail
Boreal regions contain more than half of the carbon in forested regions of the world and over 60% of the world's surface freshwater. Carbon storage and the flood control and water filtration provided by freshwaters and wetlands have recently been identified as the most important ecosystem services provided by boreal regions, with a value many times greater than current resource exploitation. Ecosystem services and sensitive ways of detecting their impairment have so far not been fully included in boreal conservation planning. Climate warming, via its effect on permafrost melting, insect damage, and forest fire, threatens to trigger large positive carbon feedbacks that may enhance the concentrations of greenhouse...
thumbnail
This study is the second attempt to use the Basal Temperature of Snow (BTS) method to map permafrost in mountainous regions of northwestern Canada. It differs from the first study which took place in Wolf Creek in terms of (1) the methodology used to evaluate BTS, (2) the strategy used to avoid spatial autocorrelation in residuals, and (3) the climatic regions investigated. Two study areas, part of the Ruby Range (61° 12' N, 138° 19' W) and Haines Summit (59° 37' N, 136° 27' W) were selected for BTS sampling based on differing climatic conditions and previous knowledge of permafrost elevations from active rock glaciers. A total of 30 BTS measurements were made in the Ruby Range in the winter of 2006 and a total...
map background search result map search result map Evaluating Climate-Induced Runoff and Temperature Change on Stream Habitat Metrics for Endangered or Threatened Fish - BOR Project FY2011 Minnesota (USA) Climate Change Project: White Pine at Year 100 (2095), assuming emissions scenario B2, Hadley3 GCM, contemporary harvest rates and intensity Minnesota (USA) Climate Change Project: Jack Pine at Year 50 (2045), assuming emissions scenario B2, Hadley3 GCM, restoration harvest rates and intensity Minnesota (USA) Climate Change Project: Sugar Maple at Year 150 (2145), assuming emissions scenario B2, Hadley3 GCM, contemporary harvest rates and intensity Impervious Surface: Projected 2050 Effects of observed and experimental climate change on terrestrial ecosystems in northern Canada: results from the Canadian IPY program Sensitivity of northern peatland carbon dynamics to Holocene climate change Airborne electromagnetic imaging of discontinuous permafrost The effect of fire and permafrost interactions on soil carbon accumulation in an upland black spruce ecosystem of interior Alaska: implications for post-thaw carbon loss Physical and ecological controls on methane release from a boreal peatland in interior Alaska Exploring the sensitivity of soil carbon dynamics to climate change, fire disturbance and permafrost thaw in a black spruce ecosystem Validation of the Basal Temperature of Snow (BTS) method to map permafrost in complex mountainous terrain, Ruby Range, Yukon Territory and Haines Summit, British Columbia “The Worst Thing We Had To Contend With”: Permafrost and Construction of the Alcan Highway Comprehensive conservation planning to protect biodiversity and ecosystem services in Canadian boreal regions under a warming climate and increasing exploitation Progress in space-borne studies of permafrost for climate science: Towards a multi-ECV approach Validation of the Basal Temperature of Snow (BTS) method to map permafrost in complex mountainous terrain, Ruby Range, Yukon Territory and Haines Summit, British Columbia Evaluating Climate-Induced Runoff and Temperature Change on Stream Habitat Metrics for Endangered or Threatened Fish - BOR Project FY2011 Physical and ecological controls on methane release from a boreal peatland in interior Alaska Exploring the sensitivity of soil carbon dynamics to climate change, fire disturbance and permafrost thaw in a black spruce ecosystem Minnesota (USA) Climate Change Project: Sugar Maple at Year 150 (2145), assuming emissions scenario B2, Hadley3 GCM, contemporary harvest rates and intensity Minnesota (USA) Climate Change Project: White Pine at Year 100 (2095), assuming emissions scenario B2, Hadley3 GCM, contemporary harvest rates and intensity Minnesota (USA) Climate Change Project: Jack Pine at Year 50 (2045), assuming emissions scenario B2, Hadley3 GCM, restoration harvest rates and intensity Airborne electromagnetic imaging of discontinuous permafrost “The Worst Thing We Had To Contend With”: Permafrost and Construction of the Alcan Highway The effect of fire and permafrost interactions on soil carbon accumulation in an upland black spruce ecosystem of interior Alaska: implications for post-thaw carbon loss Impervious Surface: Projected 2050 Effects of observed and experimental climate change on terrestrial ecosystems in northern Canada: results from the Canadian IPY program Sensitivity of northern peatland carbon dynamics to Holocene climate change Progress in space-borne studies of permafrost for climate science: Towards a multi-ECV approach Comprehensive conservation planning to protect biodiversity and ecosystem services in Canadian boreal regions under a warming climate and increasing exploitation